The Oklahoma Supreme Court says the state’s abortion law effectively bans all medication abortions in a ruling that responds to a U.S. Supreme Court request for clarification.

The Oklahoma high court had previously struck down the law in a three-paragraph opinion. The U.S. Supreme Court had accepted the challenge to the law in June, but asked the Oklahoma court to clarify what procedures are barred under the law, report the Washington Post, the New York Times, SCOTUSblog and the Los Angeles Times.

The Oklahoma law requires doctors prescribing abortion pills to follow the Food and Drug Administration protocol for dosage and other instructions. The FDA approved mifepristone, commonly referred to as RU-486, in 2000.

Since then, the Oklahoma Supreme Court says, research has shown the drug should be prescribed in a smaller dosage. In addition, doctors often use RU-486 in combination with a different drug, misoprostol, which can be taken at home. The Oklahoma law does not allow for those uses, though they have been deemed safer and more effective than the FDA protocol, the Oklahoma Supreme Court said in its Oct. 29 opinion (PDF).

“Ninety-six percent of medication abortions in the United States are now provided according to a regimen different from the one described in mifepristone’s FDA-approved label,” the court said.

The New York Times says the Oklahoma Supreme Court’s decision could make the case less attractive to the U.S. Supreme Court, which may want to consider the narrow issue of mifepristone restrictions. SCOTUSblog says the Supreme Court’s next step is unclear, though the Oklahoma ruling may deepen the conflict with a federal appeals court ruling upholding a similar Ohio law.

The case is Cline v. Oklahoma Coalition for Reproductive Justice.

Prior coverage:

ABAJournal.com: “The next big abortion case? It could be a challenge to Okla. pill regs, accepted by SCOTUS in June”